JPH02295313A - Logical computing element and controller using the same element - Google Patents

Abstract

PURPOSE:To reduce the size and price of the computing element and to improve its function by utilizing an AC electric signal or intermittent light as an input signal. CONSTITUTION:When energy is inputted to two input circuits la and 1b of an input part 1 at the same time, one output circuit 2a turns on and the other output circuit 2b turns off. Therefore, a posture or negative source voltage is outputted to the output terminal of an output part 2. Further, when the energy is inputted to neither of the two input circuits 1a and 1b of the input part 1, the input circuits 1a and 1b turn off, and consequently one output circuit 2a of the output part 2 turns off and the other output circuit 2b turns on. The negative or positive source voltage is therefore outputted to the output terminal of the output part 2 and when an ON-OFF alternating input is supplied to the two input circuits 1a and 1b at the same time, an alternating output synchronized with the input is obtained at the output terminal. Consequently, the size and price are reduced and the function is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a fail-safe logical arithmetic unit and a control device using the same arithmetic unit. <Prior Art> In recent years, the use of safety-conscious equipment has increased in many fields. Since human operations always involve errors, it is extremely important to prevent accidents caused by erroneous operations. To this end, a computing device that can process safety information reliably and without errors is essential. Even if the component parts of the computing unit that handle this safety information fail, the configuration of the computing unit performs fail-safe processing to safely control the current state of the equipment, and the structure of the equipment itself has a fail-safe structure. By doing so, it is possible to realize equipment that takes safety into consideration. Traditionally, a typical fail-safe logical operation unit is a signal relay used in railway signal equipment. Signal relays have been devised in various ways and have a proven track record as fail-safe computing devices. This is because this signal relay is specially designed so that the circuit can be constructed with the non-excitation state on the safe side, in principle, in case of power outages, disconnections, voltage drops, etc., and there is no possibility of false outputs. It is also possible to implement the function of a signal relay using an electronic circuit. For example, there is a fail-safe logic circuit described in Japanese Patent Laid-Open No. 60-68719. However, when using semiconductor elements like this logic circuit,
Since both short-circuit and open-circuit faults must be taken into account, it is necessary to devise a method to perform calculations while setting elements such as transistors in an oscillating state and making sure that the elements are not faulty. [Problems to be solved by the invention] Since signal relays use mechanical contacts, it is difficult to manufacture them in order to ensure that the state transitions to the safe side in the event of a failure, and it is difficult to miniaturize them. , it is also expensive. However, since the power used to drive the signal relay is used as the input signal, it has the advantage of completely eliminating malfunctions due to electromagnetic induction noise. On the other hand, the above fail-safe logic circuit (Japanese Patent Laid-Open No. 60-68
No. 719) is cheaper and smaller than signal relays, but since it does not use the power to drive the circuit as an input signal, it is not very long, considering the influence of electromagnetic induction noise in the signal transmission path. Not suitable for distance. For example, a fail-safe AND operator outputs an operation permission signal by ANDing a safety confirmation signal and an operation request signal, but the operation permission signal will not be output erroneously due to element failure, etc. , the operating rate is lower than that of non-failsafe computing devices. ! In places where there is a high possibility of magnetic induction noise occurring, upper and lower thresholds are certainly set for the input level, so electromagnetic induction noise will not cause malfunctions, but every time noise enters, it will be on the safe side. As the status changes to , it is inevitable that the operating rate will decrease. Furthermore, since the conversion between DC, AC, and DC is performed in each computing unit, the computing speed is limited, and it is not suitable for high-speed computing. Furthermore, in order to realize direct current/alternate current or alternating current/direct current conversion, a large amount of semiconductor elements are used, making the circuit unavoidable. Thus, the present invention maintains fail-safe properties by using an AC electric signal or intermittent light as an input signal.
Compact computing unit, lower price, improved electromagnetic induction noise resistance, improved reliability due to simplified computing unit configuration, high lii!
《Means for solving problems》 The purpose is to provide a fail-safe logical operation unit and a control device using the same operation unit that can meet the demands for higher efficiency, faster calculation and signal transmission, etc. In order to solve the above problems, a logical operator according to a first invention has: (a) an input section and an output section connected in parallel between positive and negative power supply voltages; (c) The output section is configured by connecting two input circuits in series, each consisting of a switching element operated by energy and a resistance element connected in series, and grounding the intermediate point of both human-powered circuits. , two output circuits each consisting of a switching element are connected in series, and an output terminal is connected to the midpoint of both output circuits in an elliptical configuration; In the input circuit and the output concave path on the same side with respect to positive and negative, the intermediate point between the switching element and the resistance element of the input circuit is connected to the control terminal 131l of the switching element of the output circuit. Furthermore, the fail-safe control device according to the second invention connects the output terminal of the output section of the logical operator according to the first invention to the control terminal of the switching element in the subsequent stage, and connects the switching element in the subsequent stage to the load and the power source. It is characterized by being connected in series. Furthermore, the logic operator according to the third invention has (a) an input section and an output section connected in parallel between positive and negative power supply voltages, and (a) the input section includes a switching element and a resistance element. (c) The output section is configured by connecting two output circuits each consisting of a switching element in series; (2) The switching element and the resistance element of the input section are connected in series. It is characterized in that the intermediate point and the control terminal of the switching element of each of the output circuits are connected. And, the fail-safe control device according to the fourth invention is
Connecting the output terminal of the output part of the OR'7i4 calculator according to the third invention to the control aui:t terminal of the switching element in the subsequent stage,
The feature is that the switching element in the subsequent stage is connected in series with the load and power supply. <<Operation>> In the logical arithmetic unit according to the first invention, when energy is simultaneously input to two input circuits of the input section, each input circuit is turned on. Based on this, one output circuit is turned on and the other output circuit a is turned off. Therefore, a positive or negative power supply voltage is output to the output terminal of the output section. Additionally, if no energy is input to either of the two input circuits in the input section, each input circuit is turned off.
Based on this, one output circuit of the output section is turned off and the other output circuit is turned on. Therefore, a negative or positive power supply voltage is output to the output terminal of the output section. In this way, if two input circuits have alternating inputs that are turned on and off at the same time, an alternating output that is synchronized with the inputs will be obtained at the output terminal. In the control device according to the second aspect of the invention, since the switching element connected in series with the load is coupled to the output terminal of the logical operator, only when there are alternating inputs to the two input circuits of the input section at the same time, The switching element performs a switching operation to operate a load. In the OR operator according to the third invention, when the switching element of the input section is turned on, one output circuit of the output section is turned on and the other output circuit is turned off, and the output terminal has a positive or negative signal. The voltage is output. When the switching element of the input section is off, one output circuit of the output section is off and the other output circuit is on, and a negative or positive voltage is output to the output terminal. Therefore, if the input section receives alternating input from even one of the multiple signal sources, an alternating output synchronized with the input can be obtained at the output terminal. In the control device according to the fourth aspect of the invention, a switching element connected in series with the load is coupled to the rear stage of the output terminal of the logical sum operator.
Only when there is an alternating input to the input circuit of the input section, the switching element performs a switching operation to operate the load. <<Example>> Next, an example of the present invention will be described with reference to the drawings. As shown in FIG. 1, the logic operation unit according to the first invention has positive and negative power supply voltages Vh and V1 for operating this operation unit.
Input section 1 and output section 2 are connected in parallel between the input section 1 and input section 1, and input circuit 1a and lb are connected in series, and input circuit 1a and lb are connected in series with switching elements and resistance elements operated by energy inputs INI and IN2. At the same time, the intermediate point of both input circuits is grounded, and the output section 2 is configured by connecting in series output circuits 2a and 2b consisting of switching elements operated by the input of an electric signal, and connecting both output circuits in series. It is configured by connecting the output terminal OUT to the midpoint of
The input section 1 and the output section 2 are connected to the intermediate point between the switching element and the resistance element of the input circuit and the control of the switching element of the output circuit in circuits 1a, 2a, lb, and 2b on the same side between the positive and negative sides of the power supply voltage. It consists of connecting terminals. The above midpoint does not mean the electrical midpoint with respect to positive and negative power supply voltages. Electrically, there may be some variation as long as it swings to the positive and negative sides depending on the input state. This logical operation unit can use both electrical energy and optical energy as input energy, but depending on which energy is used, the input circuits 1a, lb
The specific structure of the two is different. It is separated as follows. First Embodiment FIG. 2 shows an embodiment in which electrical energy is used as input energy. This will be explained in detail below. The input circuit 1a constituting the input section 1 includes a P-gate thyristor THP and a resistor R1, and the input circuit 1b includes an N-gate thyristor THN and a resistor R2. Moreover, the output circuit 2a is a PNP transistor TR
．． and a resistor element RS, and the output circuit 2b is composed of an NPN transistor TR2 and a resistor element Rs, respectively. In this embodiment, the alternating energy of a predetermined frequency is set to logic "1". Logic "1" is treated as not including errors due to component failures. Other conditions are
Fail-safe logical operations can be realized by treating it as a logic ``0'' that may contain errors due to component failures. Input times #! The P-gate thyristor THP 1a is turned on when the gate potential is made higher than the cathode potential, and is turned off when the gate potential is made lower than the cathode potential at a certain speed. When in the on state, the resistance value of the resistor element R1 is determined to ensure a current greater than the holding current, and the on state is latched. That is, switching occurs only when the gate of the thyristor THP receives an alternating input based on its cathode potential. Further, the N-gate thyristor THN of the input circuit 1b has P
Since it operates complementary to the gate thyristor THP, it switches only when there is an alternating input based on the anode potential, and the resistance value of the resistor R2 is also set to be the same as that of the resistor R1. The power supply potential is set so that Vh>Vm (ground potential)>V1, and the ratio of the resistance values of the output resistor elements RI1, R. , the potential of the output terminal OUT is set to be equal to Vm.The effect of the above-mentioned topology is that when a negative potential is simultaneously input to the input section, the thyristor THP of the input section is turned off, and the thyristor THP of the input section is turned off.
N is in the on state, and the transistor T R s of the output section
is in the off state and the transistor TR2 is in the on state, so the potential of the output signal OtJT with respect to the ground potential Vm becomes V1. On the other hand, if a positive potential is input to the input section at the same time, thyristor THP is turned on and THN is turned off.
Since the transistor T R 1 is in the on state and the transistor T R 2 is in the off state, the potential of the output signal OUT becomes vh. Therefore, by always keeping THP and THN in different states, the logic “
1" are input at the same time, an alternating output with respect to the ground potential Vm is obtained at the output terminal OUT, so a logic "1" is output as the calculation result. In the case of input signals of combinations other than the above, or the configuration In the case of an element failure, the output signal always takes only one potential with respect to the potential Vm, and a logic "0" is output.
》This is obvious when considering all cases since the configuration of the arithmetic unit is simple. For example, when the transistor TRI is always on and the transistor TR2 is on/off, the output OU
T becomes VM and vh, respectively, and the potential on the Vl side is not output. In addition, transistor TR1 is always in an off state,
When T R z is in on/off state, the output OUT
are Vm and Vf, respectively, and the potential on the vh side is not output. As described above, in this embodiment, alternating energy of a predetermined frequency is input as an input signal, and an AND operation is performed without performing any energy conversion such as rectification, and an output signal synchronized with the input signal is converted to alternating energy. This makes it possible to provide an AND operator that performs a fail-safe AND operation that outputs . In addition, Energy Manpower IN. By connecting IN2 and IN2 with a wired OR connection, it is possible to perform a multi-input OR operation. FIG. 3 shows an embodiment of an energy control device having a completely safe logic operation function using the logic operation unit described above. Again, it is assumed that logic '1' and logic '0' are the same as in the case of Fig. 2. In Fig. 3, THPa is a switching element operated by the output signal OUT of the logic operator. This is a P-gate thyristor, and the cathode potential is switched only by the alternating input of the gate to Vm (when the output of the logic operator is logic "1"), and Vc is the power supply potential that supplies energy to the load. If the thyristor to be used is a P-gate, set the relationship such that Vc>Vm, and if it is an N-gate, set the relationship Vc<Vm.For example, input this switching pulse to the primary side of an isolation transformer, and set it to the secondary side. If the output pulse is rectified,
It can be used as a fail-safe DC power supply. In addition, the above fail-safe logic circuit (Japanese Patent Laid-Open No. 60-68
Voltage doubler rectification may be performed using a rectifier circuit using capacitive coupling as shown in 719). In other words, thyristor TH
If the energy is output only when Pa is switching, fail-safe energy #
God will be realized. Second Embodiment FIG. 4 shows an example in which optical energy is used as the input energy of the fail-safe logic operator in FIG. 1. In FIG. Also shown is an energy control device using In this embodiment, intermittent light PH of a predetermined frequency is used.
Let I and PH2 be logical “1”. Logic "1" is treated as not including errors due to component failures. Fail-safe logical operations can be realized by treating other states as logic "O" that may contain errors due to component failures. The power supply potential is Vh>Vm>
Vj! It is said that there is a relationship between VC is the power supply potential that supplies energy to the load L (the thyristor used is P
In the case of a gate, the relationship is set such that V c > V m. ) In this embodiment, phototransistors P T s , P are used as switching elements of the input circuit 1a1b of the input section.
Except for the fact that Tz is used, the other configurations are the same as those of the first embodiment. By simultaneously inputting signal light to the phototransistors PT1 and PTz in the input section, P T
s and P T2 turn on at the same time. The switching transistor TR in the output section. The base potential of TR. becomes a substantially positive power supply potential vh, and the base potential of TR. turns on. At the same time, T.R.
The base potential of TR2 becomes almost a negative power supply potential vi, and TR2
is off, TR. turns on and TR2 turns off,
Since the gate potential of thyristor T}{P becomes higher than the ground potential Vm of the cathode, thyristor THP is turned on. Furthermore, when no signal light is incident on both phototransistors PT1 and PT2, p”rt,
Both PT2 are in the off state. The base potential of the switching transistor TRI is the ground potential Vm, and TR1
At the same time as TRI is turned off, the base potential of TR2 becomes approximately Vm, and TR2 is turned on. When TRI is turned off and TR2 is turned on, the gate potential of thyristor THP becomes Vm, and THP is turned off. Only by inputting synchronized intermittent light to the phototransistors PT1 and PT2 through the series of operations described above, an output pulse synchronized with the input intermittent light can be obtained at the output terminal OUT. On the other hand, consider, for example, the case where intermittent light is incident on the phototransistor PT1 and DC light is incident on the phototransistor PT2. Repeat off. Since DC light is incident on PT2, it remains on, and PT. is on and PT2
is on, TR1 and TR2 are both on, so if the ratio of the resistance values of resistors R and Re is set to 1=1, the gate potential of thyristor THP is approximately Vm, and the state of THP is It is not a condition that changes. Also, P
When T1 is off and PT2 is on, TRI is off and TR2 is on, so the gate potential of thyristor THP becomes negative and thyristor THP can be turned off. However, in this case, the THP on condition does not hold, so the THP cannot perform a switching operation. If we consider all the combinations of light incident on the phototransistors PT1 and PT2 in this way, we can see that the switching operation of the thyristor THP occurs only when synchronized intermittent light is simultaneously input to PT1 and PT2. ．． Furthermore, even if a wire breaks somewhere in this circuit, it is impossible to perform the switching operation of the thyristor THP. It is well known that resistive elements do not have conduction failures, but only disconnection failures, so even if a transistor or thyristor other than a resistor suffers a conduction failure, the switching operation of the thyristor THP is impossible. From the above, it is clear that the prescribed intermittent light, which does not include errors due to failures in elements or transmission lines, is defined as a logic “1”.
It is suitable for processing safety information where DC light or no light is assumed to be a logic "O", and "1" is considered reliable. In each of the above embodiments, each input circuit 1a, lb of the input section 1
In the above, we explained the case where it was used as an AND operator by inputting two systems of electrical signals or optical signals, respectively. By inputting to a and lb, it is possible to use this logical operator as an OR operator. FIG. 5 shows the basic configuration of a fail-safe OR operator according to the third invention and the configuration of an example of a control device using the OR operator. This OR operator has an input part IE and an output part 2E connected in parallel between the power supply voltages 10Vcc and -Vcc for operating this operator, and the input part 1 has a switching element T1 and a resistance element R1. Connect in series to form an ellipse,
The output section 2 includes a switching element and a resistive element T2, Rs
, T3, and R4 are connected in series.
a and 2b are connected in series, and a resistive element is connected between the intermediate point between switching element /r1 and resistive element R1 of the input section and the control terminal of switching elements T2 and T3 of each output circuit 2a and 2b. They are connected via R2 in an oval configuration. This OR operator can also use either electrical energy or optical energy as input energy. Since FIG. 5 shows an embodiment in which optical energy is used as input energy, a phototransistor is used as the switching element T1 in the input stage. It is clear from the above explanation that when electrical energy is used as input energy, a thyristor can be used instead of this phototransistor. Next, we will explain the effect of the ellipse in Figure 5. When no signal light is incident on the phototransistor T1, the base potential of the transistors T2 and T3 becomes a negative power supply voltage, so the NPN transistor T2 is in an off state and the PNP transistor T3 is in an on state. Therefore,
The potential of the output terminal OUT is approximately equal to the negative power supply voltage. Therefore, in a control device configured by connecting the thyristor T4 as a switching element to the output terminal OUT and connecting the load L to the thyristor T4, the thyristor T4 is in an off state. On the other hand, when signal light is incident on the phototransistor T1, the base potentials of the transistors T2 and T are almost at the positive power supply voltage, so the NPN transistor T2 is in the on state and the PNP transistor T is in the on state. It is in the off state. Therefore, the potential of the output terminal OUT becomes approximately equal to the positive power supply voltage. Therefore, thyristor T4 is turned on. By continuing the above operations and using intermittent light as an input signal, it is possible to obtain an output signal as intermittent energy synchronized with the input signal. Therefore, by inputting multiple synchronized intermittent lights to phototransistor T1. For example, you can perform a logical sum operation. In this circuit, even if a short-circuit or open-circuit failure occurs in each transistor, no output as intermittent energy is output to the output terminal OUT, so the thyristor T
It is impossible to switch 4. Further, even if each resistor causes an open failure, the potential of the output terminal OUT does not change, so it is impossible to switch the thyristor T4. Furthermore, if there is a failure in the thyristor T4 or the load L of the thyristor, it is clear from this circuit that no output as intermittent energy will be output, so it can be said that this circuit is a fail-safe OR operator. From the above, a prescribed intermittent light that does not include errors due to failures on the element or transmission line is defined as logic "1", and others are defined as logic "0" that may include failure errors.
It can be used to process safety information where logic "1" is considered reliable information. In the above embodiment, the switching transistors in the output section can function similarly by reversing the arrangement positions of the PNP type and NPN type from the example shown. Furthermore, the switching element connected after the output terminal of the logical operator of the control device is not limited to a thyristor, but a fail-safe transistor combination circuit can also be used, although the circuit configuration is somewhat complicated. <<Effects of the Invention>> As described above, according to the logical operator according to the first invention, the fail-safe logical product operator can be made smaller and less expensive, and the electromagnetic induction in the signal transmission line can be reduced. It eliminates the effects of noise, and promotes higher functionality in embedded devices, making it extremely useful in practical terms. Also, depending on how the input signals are input, it can be used as either an AND operator or an OR operator. Furthermore, recent advances in semiconductor technology have made it possible to integrate into a single chip, making it possible to construct arithmetic units with complex logic that are significantly smaller than conventional arithmetic units. By using high-speed optical semiconductor elements, the calculation speed can be expected to be equivalent to that of a normal control computer. Further, according to the second invention, a fail-safe control device can be provided. Furthermore, according to the logical operator according to the third invention, a fail-safe logical sum operator can be obtained with a simple configuration. According to the fourth invention, it is possible to provide a fail-saving control device using the third invention. When using an optical sensor in the input section, it must be at a predetermined frequency so that it will not malfunction even if direct current light such as sunlight gets mixed in due to a failure in the transmission line, or will not include an erroneous output signal due to a failure in the arithmetic unit. By setting intermittent light to logic "1" and setting DC light or no light that may contain errors at the time of failure to logic "0", intermittent light at a predetermined frequency can be used in the natural world or in computing devices. You can select a state that does not exist in the environment in which it is installed. Furthermore, even in a control device using an optical logic processor, it can be assumed that there are no errors such as failures, since it is possible to simultaneously confirm that the output stage of the preceding processor is normal. Logic “1” and logic “l”
By taking the logic product with , it is possible to output a logical ``1'' when the arithmetic unit is normal, and a logical ``0'' under all other input conditions or when there is a failure.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the first invention, FIG. 2 is an electric circuit diagram of a logical operator which is an embodiment of the first invention,
FIG. 3 is a circuit diagram showing the configuration of a control device using the logical operation unit of FIG. 2, FIG. 4 is a circuit diagram showing an embodiment of the second invention, and FIG. 1 is a circuit diagram showing an embodiment of the invention. 1... Input section, la, lb... Input circuit, 2... Output section, 2a. 2b...Output circuit, vh, v, 5...Power supply voltage, IN. , IN2... Input energy patent supplier Nippon Signal Co., Ltd. vl 1711 + Vcc vh Figure 4

Claims (4)

[Claims] (1) (a) It has an input part and an output part connected in parallel between positive and negative power supply voltages, and (b) The input part has a switching element operated by input energy and a resistance element connected in series. (c) The output section has two output circuits each consisting of a switching element connected in series, and the intermediate point between both input circuits is grounded. (d) The input section and the output section are configured by connecting the switching element and the resistance element of the input circuit between the input circuit and the output circuit on the same side with respect to the positive and negative power supply voltages. A logical operator, in which an intermediate point and a control terminal of a switching element of the output circuit are connected. (2) Connecting the output terminal of the output section of the logical operator according to claim 1 to the control terminal of the subsequent switching element,
A fail-safe control device in which the subsequent switching element is connected in series between the load, power supply, and ground. (3) (a) It has an input part and an output part connected in parallel between positive and negative power supply voltages, (b) The input part is formed by connecting a switching element and a resistance element in series, and (c) The output section is formed by connecting two output circuits each consisting of a switching element in series, and (d) the intermediate point between the switching element and the resistance element of the input section is connected to the control terminal of the switching element of each of the output circuits. A logical summation unit connected between . (4) The output terminal of the output section of the logical OR operator according to claim 3 is connected to the control terminal of the switching element in the subsequent stage, and the switching element in the subsequent stage is connected between the load, the power supply, and the ground. A fail-safe control device connected in series.